Pressure producing means for hydraulic pressure systems



July 20, 1937. c. v. GARDNER 2,087,509

PRESSURE PRODUCING MEANS FOR HYDRAULIC PRESSURE SYSTEMS Filed Nov. 29, 1935 ATTORN EYS.

Patented July 20, 1937 `UNITI-:D 'STATES liaxrlezu'rj OFFICE PRESSURE PRODUCING MEANS FOR HY DRA'ULIC PRESSURE SYSTEMS Clarence V. Gardner, Detroit, Mich., assignor to Hydraulic Brake Company, Detroit, Mich., a corporation of California Application November 29, 1935, Serial No. 52,000

' 6 Claims.

. dual braking system for operating the brakes associated with the wheels of a motor vehicle and to so construct and arrange. the separate systems that they hay be operated by a single operating means.

lAvfurther object of the invention is to provide a duel braking system for operating the brakes associated with the wheels of a motor vehicle and to so construct vand arrange the same that in I normal operation the systems are equalized, and

in the event of the failure of one of the systems,

due to breakage or leakage, the remaining system may be effectively operated.

Other objects and advantages of the inventio will appear from the following description taken in connection with the drawing forming a part of this specification. and in which,-

Fig. 1 is a schematic view of a hydraulic brake system embodying'the invention;` and Fig. 2 is a vertical, sectional view of the master operating unit.

Referring to the drawing for more specific details of the invention. I0 represents a fixed support which may be a part of the motor vehicle chassis frame or a support suitably secured to the frame. Preferably the support is finished on its upper side to provide a smooth polished *sur-l face, the purpose of which Jwill hereinafter appear. The body ofthe support is provided with a plurality of spaced longitudinal slots I2, I4 and. I6, and one endlof the support is bent upwardly normal to its body portion as at I8.

Slidably mounted on the polished surface of the support I ll is a casting comprising opposed cylinders 20 and 22 with reservoirs 24 and 26 superimposed on the cylinders. The cylinder 20 communicates with the reservoir 24 by way of ports 28 and 80, and the cylinder 22 communicates with the reservoir 26 by way of ports 82 and 34. The reservoirs have conventional llingopenings I6 and 88 closed by suitable plugs 40 and 42, and are vented as indicated at 44 and 46.

As shown, the cylinder 20 has a dependent boss surface of the support (Cl. Gil-454.5)

48 and the cylinder 22 has a dependent 'boss 60. These bosses have highly polished at surfaces of suflicient diameter` to straddle theslots I2 and |6, respectively, and slidably engage the polished I0. Threaded into the bosses from the back of the support I0 are retaining bolts 52 and 64. These bolts alsoserve to guide the movements ofthe cylinders and reservoirs, and connected between one of the bolts andthe iixed support 66 isa retractor spring 68.

A The cylinder 20 has a discharge port .60 con.

trolledby a two-way valve 62, and connected to the discharge port isa uid 4pressure delivery pipe 64 having branches 68 and 88 connected respectively to fluid pressure actuated motors. 10 ar ranged for the 'actuationy of brakes associated with the front wheels of a motorI vehicle; and

the cylinder 22 has a discharge port '|2 controlled by a two-way valve 1 4, and connected to the discharge port 'I2 is a uid pressure delivery pipe .16 having branches 18 and 80 connected respectively to fluid pressure actuated motors 82 arranged for the actuation of brakes associated with'the rear `wheels of the vehicle.

Each of the brake structures includes a ilxed support or backing plate 84, a rotatable drum 88 associated therewith, corresponding friction elementsor shoes 88 and 90 pivoted on the backing plate.- and a fluid pressure motor corresponding to v i' theiluid pressure motors 10 lor 82 suitably con-` nected to the separable ends of the friction elements or shoes for spreading the 'shoes into engagement with the drum 86 against the resistance of a retractile spring 84. A piston 96 reciprocable in the cylinder 20 is retained against displacement by a washer 98 held against a shoulder |00 in the open end of the cylinder 20 by a s plit ring |02 seated in a circumferential groove. This piston has a reduced body portion providing in commotion with the wail of the cylinder 20 an annular chamber |04 com-- municating with the reservoir 24 by way of port 28. The skirt 'of the piston has thereon a leakproof washer |06 which prevents seepage of fluid from the cylinder past the piston, and the head of the piston has a plurality of ports |08 provid.

ing communications between the annular cham-- ber |04'and that portion of the cylinder forward of the piston. n

A collapsible leak-proof cup ||0 on the head of the piston controls the ports |08. 'I'his cup is held against displacement by a spring ||2 interc .9,087,509 ports, pistons in the cylinders, means supporting the cylinders for reciprocation, fluid pressure actuated motors connected to the discharge portk of each cylinder, means retaining one of the pistons against movement, and means for actuating the other piston.

5. A iluid braking system comprising a duplex pressure producing device including a single casting, cylinders therein arranged head to head, a member supporting the casting for longitudinal reciprocatic'in, rluid pressure actuated motors connected to the respective cylinders, pistons in the cylinders, a fixed member retaining one of -means on the bracket resisting movement of one of the pistons, and means for actuating the other piston. l

CLARENCE V. GARDNER. 

